1. Field of the Invention
The present invention relates to an audio encoding method and apparatus and an audio decoding method and apparatus in which sound images can be localized at any desired position for each object audio signal.
2. Description of the Related Art
In general, in multi-channel audio encoding and decoding techniques, a number of channel signals of a multi-channel signal are downmixed into fewer channel signals, side information regarding the original channel signals is transmitted, and a multi-channel signal having as many channels as the original multi-channel signal is restored.
Object-based audio encoding and decoding techniques are basically similar to multi-channel audio encoding and decoding techniques in terms of downmixing several sound sources into fewer sound source signals and transmitting side information regarding the original sound sources. However, in object-based audio encoding and decoding techniques, object signals, which are basic elements (e.g., the sound of a musical instrument or a human voice) of a channel signal, are treated the same as channel signals in multi-channel audio encoding and decoding techniques and can thus be coded.
In other words, in object-based audio encoding and decoding techniques, each object signal is deemed the entity to be coded. In this regard, object-based audio encoding and decoding techniques are different from multi-channel audio encoding and decoding techniques in which a multi-channel audio coding operation is performed simply based on inter-channel information regardless of the number of elements of a channel signal to be coded.